Compositions and methods comprising energy absorbing compounds for follicular delivery

ABSTRACT

The present invention provides compositions comprising energy (e.g., light) absorbing submicron particles (e.g., nanoparticles comprising a silica core and a gold shell) and methods for delivering such particles via topical application. This delivery is facilitated by application of mechanical agitation (e.g. massage), acoustic vibration in the range of 10 Hz-20 kHz, ultrasound, alternating suction and pressure, and microjets.

RELATED APPLICATION DATA

This application claims the benefit of U.S. provisional patentapplication Ser. No. 61/636,381, filed Apr. 20, 2012, the entirecontents of which are incorporated herein by this reference.

This application may contain subject matter that is related to thatdisclosed and claimed in U.S. patent application publication No.2012/0059307 A2, published on Mar. 8, 2012, the entire contents of whichare incorporated herein by this reference.

BACKGROUND OF THE INVENTION

Acne vulgaris is a follicular skin disease that is characterized by theappearance of comedones, papules, nodules, and cysts. Comedones are hairfollicles that are blocked with a keratin plug. Open comedones, those inwhich the keratin plug is visible, form “black heads” and closedcomedones form “whiteheads” that often progress to inflamed papules,nodules, and cysts. The presence of bacteria in a follicle attractswhite blood cells to the follicle, which can cause an inflammatoryresponse seen as papules (red bumps), pustules, and nodules. Acne may beminor, where only a few comedones or papules are present, or it may behighly inflammatory and leave disfiguring scars. Improved methods oftreating or ameliorating follicular skin diseases, such as acnevulgaris, are required.

SUMMARY OF THE INVENTION

As described below, the present invention provides compositionscomprising energy (e.g., light) absorbing submicron particles (e.g.,nanoparticles comprising a silica core and a gold shell) and methods fordelivering such particles via topical application into a hair follicle,sebaceous duct, and/or sebaceous gland. In certain embodiments, thisdelivery is facilitated by application of mechanical agitation (e.g.massage), acoustic vibration in the range of 10 Hz-20 kHz, ultrasound,alternating suction and pressure, and microjets.

In one aspect, the invention generally provides methods of treating orameliorating a follicular skin disease (e.g., acne) of a subject (e.g.,human). The method involves topically applying a formulation containinga sub-micron particle containing a light absorbing compound to asubject's skin; facilitating delivery of the compound to a hairfollicle, sebaceous gland, sebaceous gland duct, or infundibulum of theskin by mechanical agitation, acoustic vibration, ultrasound,alternating suction and pressure, or microjets; and exposing thesub-micron particle to energy activation, thereby treating thefollicular skin disease.

In another aspect, the invention provides a method of treating orameliorating a follicular skin disease of a subject, the methodinvolving topically applying a formulation containing a photoactivecompound, photodynamic therapy (PDT) pro-drug or PDT drug to the skin ofa subject, facilitating delivery of the compound to a hair follicle,sebaceous gland, sebaceous gland duct, or infundibulum of the skin bymechanical agitation, acoustic vibration, ultrasound, alternatingsuction and pressure, or microjets; and exposing the photoactivecompound, photodynamic therapy (PDT) pro-drug to energy activation,thereby treating the follicular disorder.

In another aspect, the invention provides a method of improving theappearance of enlarged pores in the skin of a subject, the methodinvolving topically applying a formulation containing a sub-micronparticle containing a light absorbing compound to a subject's skin;facilitating delivery of the compound to a hair follicle, sebaceousgland, sebaceous gland duct, or infundibulum of the skin by mechanicalagitation, acoustic vibration, ultrasound, alternating suction andpressure, or microjets; and exposing the sub-micron particle to energyactivation, thereby treating the follicular skin disease.

In another aspect, the invention provides a method for permanentlyremoving lightly pigmented or thin hair of a subject, the methodinvolving topically applying a light-absorbing compound to the skin of asubject, and exposing the compound to energy activation, therebypermanently removing the hair.

In another aspect, the invention provides a method for permanentlyremoving lightly pigmented or thin hair of a subject, the methodinvolving epilating hair from a follicle of the subject; topicallyapplying a light-absorbing compound to the skin of a subject, andexposing the compound to energy activation, thereby permanently removingthe hair. In one embodiment, the compound is a nanoparticle containing asilica core and a gold shell. In another embodiment, energy activationis accomplished with a pulsed laser light that delivers light energy ata wavelength that is absorbed by the particle. In another embodiment,the skin is prepared for the method by heating, by removing thefollicular contents, and/or by epilation. In another embodiment, thetopically applied sub-micron particles are wiped from the skin prior toenergy activation using acetone.

In another aspect, the invention provides a method of facilitatingdelivery of a light absorbing compound to a target volume within theskin of a subject, the method involving topically applying a formulationcontaining a light absorbing compound to a subject's skin to deliver thecompound to a reservoir within the skin; facilitating delivery of thecompound to a target volume within the skin of the subject byirradiating the skin with a first series of light pulses; and exposingthe light absorbing compound to a second series of light pulses to heatthe compound and thermally damage the target volume to achieve atherapeutic effect.

In another aspect, the invention provides a method of facilitatingdelivery of a light absorbing compound to a target volume within theskin of a subject, the method involving topically applying a formulationcontaining a light absorbing compound to a subject's skin; facilitatingdelivery of the compound to a reservoir in the skin by mechanicalagitation; facilitating delivery of the compound to a target volumewithin the skin by applying a train of low-energy laser pulses eachpulse lasting for a microsecond or less to drive the material into thetarget volume; and exposing the light absorbing compound to a secondseries of low-energy laser pulses to heat the compound and thermallydamage the target volume to achieve a therapeutic effect.

In various embodiments of any of the above aspects or other aspects ofthe invention delineated herein, the sub-micron particle, nanoparticle,or nanoshell is coated with PEG. In other embodiments of the aboveaspects, the sub-micron particle is a nanoparticle containing a silicacore and a gold shell, optionally coated with PEG. In certainembodiments, the nanoparticle or nanoshell is about 50-300 nm (e.g., 50,75, 100, 125, 150, 175, 200, 300 nm). In particular embodiments, thenanoparticle is coated with PEG. In embodiments of the invention, energyactivation is accomplished with a pulsed laser light that delivers lightenergy at a wavelength that is absorbed by the particle. In otherembodiments, the skin is prepared for the method by heating (e.g., to atleast about 35-42° C.), by removing the follicular contents, and/or byepilation. In other embodiments, the follicular contents are removed bya method comprising contacting the follicle pore with adhesive polymers.In other embodiments, the topically applied sub-micron particles arewiped from the skin prior to energy activation. In still otherembodiments, the topically applied sub-micron particles are wiped fromthe skin with acetone. In other embodiments, the follicular skin diseaseis acne vulgaris. In other embodiments, energy activation is carried outby irradiation of the skin with a laser. In other embodiments, theultrasound energy has a frequency in the range of 20 kHz to 500 kHz. Inother embodiments, the skin is heated before, during, or after topicalapplication to about 42° C. or to a temperature sufficient to assist infollicular delivery. In other embodiments, the heating is accomplishedvia ultrasound. In other embodiments, the heating is not sufficient tocause pain, tissue damage, burns, or other heat-related effects in theskin. In other embodiments, the formulation contains a component (e.g.,ethanol) having high volatility. In other embodiments, the formulationcontains one or more of ethanol, isopropyl alcohol, propylene glycol, asurfactant, and/or isopropyl adipate. In other embodiments, theformulation contains hydroxypropylcellulose (HPC) and carboxymethylcellulose (CMC). In other embodiments, the formulation contains any oneor more of water, ethanol, propylene glycol, polysorbate 80, diisopropyladipate, phospholipon, and thickening agents. In other embodiments, theformulation is a liposomal formulation.

Composition.

In another aspect, the invention provides a composition comprising acosmetically acceptable carrier and a plurality of plasmonicnanoparticles in an amount effective to induce thermomodulation in atarget tissue region with which the composition is topically contacted.

In one embodiment, the plasmonic nanoparticles are activated by exposureto energy delivered from a nonlinear excitation surface plasmonresonance source to the target tissue region. In another embodiment, theplasmonic nanoparticle comprises a metal, metallic composite, metaloxide, metallic salt, electric conductor, electric superconductor,electric semiconductor, dielectric, quantum dot or composite from acombination thereof. In yet another embodiment, a substantial amount ofthe plasmonic particles present in the composition comprisegeometrically-tuned nanostructures.

In one embodiment, the plasmonic particles comprise any geometric shapecurrently known or to be created that absorb light and generate plasmonresonance at a desired wavelength, including nanoplates, solidnanoshells, hollow nanoshells, nanorods, nanorice, nanospheres,nanofibers, nanowires, nanopyramids, nanoprisms, nanostars or acombination thereof. In another embodiment, the plasmonic particlescomprise silver, gold, nickel, copper, titanium, silicon, galadium,palladium, platinum, or chromium.

In one embodiment, the cosmetically acceptable carrier comprises anadditive, a colorant, an emulsifier, a fragrance, a humectant, apolymerizable monomer, a stabilizer, a solvent, or a surfactant. In oneparticular embodiment, the surfactant is selected from the groupconsisting of sodium laureth 2-sulfate, sodium dodecyl sulfate, ammoniumlauryl sulfate, sodium octech-1/deceth-1 sulfate, lipids, proteins,peptides or derivatives thereof. In another specific embodiment thesurfactant is present in the composition in an amount between about 0.1and about 10.0% weight-to-weight of the carrier.

In one embodiment, the solvent is selected from the group consisting ofwater, propylene glycol, alcohol, hydrocarbon, chloroform, acid, base,acetone, diethyl-ether, dimethyl sulfoxide, dimethylformamide,acetonitrile, tetrahydrofuran, dichloromethane, and ethylacetate.

In another embodiment, the composition comprises plasmonic particlesthat have an optical density of at least about 1 O.D. at one or morepeak resonance wavelengths.

In yet another embodiment, the plasmonic particles comprise ahydrophilic or aliphatic coating, wherein the coating does notsubstantially adsorb to skin of a mammalian subject, and wherein thecoating comprises polyethylene glycol, silica, silica-oxide,polyvinylpyrrolidone, polystyrene, a protein or a peptide.

In one embodiment, the thermomodulation comprises damage, ablation,lysis, denaturation, deactivation, activation, induction ofinflammation, activation of heat shock proteins, perturbation ofcell-signaling or disruption to the cell microenvironment in the targettissue region.

In another embodiment, the target tissue region comprises a sebaceousgland, a component of a sebaceous gland, a sebocyte, a component of asebocyte, sebum, or hair follicle infundibulum. In a specificembodiment, the target tissue region comprises a bulge, a bulb, a stemcell, a stem cell niche, a dermal papilla, a cortex, a cuticle, a hairsheath, a medulla, a pylori muscle, a Huxley layer, or a Henle layer.

In another aspect, the invention provides a method for performingtargeted ablation of a tissue to treat a mammalian subject in needthereof, comprising the steps of i) topically administering to a skinsurface of the subject a composition of the invention as describedabove; ii) providing penetration means to redistribute the plasmonicparticles from the skin surface to a component of dermal tissue; andiii) causing irradiation of the skin surface by light.

In one embodiment, the light source comprises excitation of mercury,xenon, deuterium, or a metal-halide, phosphorescence, incandescence,luminescence, light emitting diode, or sunlight.

In another embodiment, the penetration means comprises high frequencyultrasound, low frequency ultrasound, massage, iontophoresis, highpressure air flow, high pressure liquid flow, vacuum, pre-treatment withfractionated photothermolysis or dermabrasion, or a combination thereof.

In yet another embodiment, the irradiation comprises light having awavelength of light between about 200 nm and about 10,000 nm, a fluenceof about 1 to about 100 joules/cm², a pulse width of about 1femptosecond to about 1 second, and a repetition frequency of about 1 Hzto about 1 THz.

In another aspect, the invention provides a composition comprising acosmetically acceptable carrier, an effective amount of sodium dodecylsulfate, and a plurality of plasmonic nanoparticles in an amounteffective to induce thermal damage in a target tissue region with whichthe composition is topically contacted, wherein the nanoparticles havean optical density of at least about 1 O.D. at a resonance wavelength ofabout 810 nanometers or 1064 nanometers, wherein the plasmonic particlescomprise a silica coating from about 5 to about 35 nanometers, whereinthe acceptable carrier comprises water and propylene glycol.

In still another aspect, the invention provides a system for laserablation of hair or treatment of acne comprising a composition of theinvention as described above and a source of plasmonic energy suitablefor application to the human skin.

The invention provides compositions, methods and systems for treatingfollicular skin diseases. Compositions and articles defined by theinvention were isolated or otherwise manufactured in connection with theexamples provided below. Other features and advantages of the inventionwill be apparent from the detailed description, and from the claims.

DEFINITIONS

Unless defined otherwise, all technical and scientific terms used hereinhave the meaning commonly understood by a person skilled in the art towhich this invention belongs. The following references provide one ofskill with a general definition of many of the terms used in thisinvention: Singleton et al., Dictionary of Microbiology and MolecularBiology (2nd ed. 1994); The Cambridge Dictionary of Science andTechnology (Walker ed., 1988); The Glossary of Genetics, 5th Ed., R.Rieger et al. (eds.), Springer Verlag (1991); and Hale & Marham, TheHarper Collins Dictionary of Biology (1991). As used herein, thefollowing terms have the meanings ascribed to them below, unlessspecified otherwise.

By “ameliorate” is meant decrease, suppress, attenuate, diminish,arrest, or stabilize the development or progression of a skin disease orcondition. One exemplary skin condition is acne vulgaris

In this disclosure, “comprises,” “comprising,” “containing” and “having”and the like can have the meaning ascribed to them in U.S. patent lawand can mean “ includes,” “including,” and the like; “consistingessentially of” or “consists essentially” likewise has the meaningascribed in U.S. patent law and the term is open-ended, allowing for thepresence of more than that which is recited so long as basic or novelcharacteristics of that which is recited is not changed by the presenceof more than that which is recited, but excludes prior art embodiments.

“Detect” refers to identifying the presence, absence or amount of theanalyte to be detected.

By “effective amount” is meant the amount of a required to amelioratethe symptoms of a disease relative to an untreated patient. Theeffective amount of active compound(s) used to practice the presentinvention for therapeutic treatment of a disease varies depending uponthe manner of administration, the age, body weight, and general healthof the subject. Ultimately, the attending physician or veterinarian willdecide the appropriate amount and dosage regimen. Such amount isreferred to as an “effective” amount.

By “energy activation” is meant stimulation by an energy source thatcauses thermal or chemical activity. Energy activation may be by anyenergy source known in the art. Exemplary energy sources include alaser, ultrasound, acoustic source, flashlamp, ultraviolet light, anelectromagnetic source, microwaves, or infrared light. An energyabsorbing compound absorbs the energy and become thermally or chemicallyactive.

As used herein, “obtaining” as in “obtaining an agent” includessynthesizing, purchasing, or otherwise acquiring the agent.

The phrase “pharmaceutically acceptable carrier” as used herein means apharmaceutically acceptable material, composition or vehicle, such as aliquid or solid filler, diluent, excipient, solvent or encapsulatingmaterial, involved in carrying or transporting a energy activatablematerial of the present invention within or to the subject such that itcan performs its intended function. Each carrier must be “acceptable” inthe sense of being compatible with the other ingredients of theformulation and not injurious to the patient. Some examples of materialswhich can serve as pharmaceutically acceptable carriers include: sugars,such as lactose, glucose and sucrose; starches, such as corn starch andpotato starch; cellulose, and its derivatives, such as sodiumcarboxymethyl cellulose, ethyl cellulose and cellulose acetate; powderedtragacanth; malt; gelatin; talc; excipients, such as cocoa butter andsuppository waxes; oils, such as peanut oil, cottonseed oil, saffloweroil, sesame oil, olive oil, corn oil and soybean oil; glycols, such aspropylene glycol; polyols, such as glycerin, sorbitol, mannitol andpolyethylene glycol; esters, such as ethyl oleate and ethyl laurate;agar; buffering agents, such as magnesium hydroxide and aluminumhydroxide; alginic acid; pyrogen-free water; isotonic saline; Ringer'ssolution; ethyl alcohol; phosphate buffer solutions; and other non-toxiccompatible substances employed in pharmaceutical formulations. Preferredcarriers include those which are capable of entering a pore by surfaceaction and solvent transport such that the energy activatable materialis carried into or about the pore, e.g., into the sebaceous gland, tothe plug, into the infundibulum and/or into the sebaceous gland andinfundibulum.

By “reduces” is meant a negative alteration of at least 10%, 25%, 50%,75%, or 100%.

By “reference” is meant a standard or control condition.

By “subject” is meant a mammal, including, but not limited to, a humanor non-human mammal, such as a bovine, equine, canine, ovine, or feline.

Ranges provided herein are understood to be shorthand for all of thevalues within the range. For example, a range of 1 to 50 is understoodto include any number, combination of numbers, or sub-range from thegroup consisting 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16,17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34,35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, or 50.

As used herein, the terms “treat,” treating,” “treatment,” and the likerefer to reducing or ameliorating a disorder and/or symptoms associatedtherewith. It will be appreciated that, although not precluded, treatinga disorder or condition does not require that the disorder, condition orsymptoms associated therewith be completely eliminated.

Unless specifically stated or obvious from context, as used herein, theterm “or” is understood to be inclusive. Unless specifically stated orobvious from context, as used herein, the terms “a”, “an”, and “the” areunderstood to be singular or plural.

Unless specifically stated or obvious from context, as used herein, theterm “about” is understood as within a range of normal tolerance in theart, for example within 2 standard deviations of the mean. About can beunderstood as within 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, 0.5%,0.1%, 0.05%, or 0.01% of the stated value. Unless otherwise clear fromcontext, all numerical values provided herein are modified by the termabout.

The recitation of a listing of chemical groups in any definition of avariable herein includes definitions of that variable as any singlegroup or combination of listed groups. The recitation of an embodimentfor a variable or aspect herein includes that embodiment as any singleembodiment or in combination with any other embodiments or portionsthereof.

Any compositions or methods provided herein can be combined with one ormore of any of the other compositions and methods provided herein,

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a micrograph showing thermal damage to the follicularepithelium and part of the sebaceous gland following delivery of ananoshell suspension by massage.

FIG. 2 is a photograph showing the skin surface after application of thenanoshell formulation with ultrasound facilitated delivery. Excessformulation was wiped from the skin before this photograph was taken.

FIG. 3 is a micrograph showing a follicle filled with dark colorednanoshells following ultrasound facilitated delivery. No nanoshells arenoted in the epidermis or the dermis.

FIG. 4 is a micrograph showing a hair follicle and surrounding skinafter ultrasound delivery of nanoshells and laser irradiation visualizedby hematoxylin and eosin (H&E stain). Selective thermal damage aroundthe follicle is shown by the added black delineation.

FIG. 5 is a photograph showing the skin surface. Accumulation ofnanoshells in the follicles is seen.

FIG. 6 is a micrograph showing a follicle having a significantaccumulation of nanoshells.

FIG. 7 is a micrograph showing localized thermal damage to a folliculeencompassing the sebaceous gland visualized using H&E stain.

FIG. 8 is a table showing the efficacy of nanoshell delivery followed bylaser treatment in a human clinical trial of back acne.

DETAILED DESCRIPTION OF THE INVENTION

The invention features compositions comprising light/energy absorbingcompounds and methods that are useful for their topical delivery to atarget (e.g., a follicle, follicular infundibulum, sebaceous gland) forthe treatment of a follicular disease.

Follicular Disease Pathogenesis

Sebaceous glands are components of the pilosebaceous unit. They arelocated throughout the body, especially on the face and upper trunk, andproduce sebum, a lipid-rich secretion that coats the hair and theepidermal surface. Sebaceous glands are involved in the pathogenesis ofseveral diseases, the most frequent one being acne vulgaris. Acne is amultifactorial disease characterized by the occlusion of follicles byplugs made out of abnormally shed keratinocytes of the infundibulum(upper portion of the hair follicle) in the setting of excess sebumproduction by hyperactive sebaceous glands.

The infundibulum is an important site in the pathogenesis of manyfollicular diseases (e.g., acne). There is evidence that abnormalproliferation and desquamation of infundibular keratinocytes leads tothe formation of microcomedones and, subsequently, to clinically visiblefollicular “plugs” or comedones. Because the architecture of theinfundibulum is important in the pathogenesis of acne, the selectivedestruction of this portion of the follicle through energy activatablematerial-assisted energy, e.g., laser, targeting eliminates or reducesthe site of pathology.

Topical Delivery of Light/Energy Absorbing Compounds

The invention provides delivery of light/energy absorbing compounds viatopical application into skin appendages of the follicle, specificallyfollicular infundibulum and the sebaceous gland. In one embodiment, suchcompounds are useful for the treatment of follicular diseases, such asacne (e.g., acne vulgaris). The introduction of a energy activatablecompounds in sebaceous glands followed by exposure to energy (light)with a wavelength that corresponds to the absorption peak of thechromophore will increase the local absorption of light in tissue andlead to selective thermal damage of sebaceous glands.

Skin Preparation

If desired, the skin is prepared by one or a combination of thefollowing methods. Delivery of light absorbing compounds may befacilitated by epilation of hair, which is performed prior to topicalapplication of the light absorbing compounds.

Optionally, the skin is degreased prior to application of the lightabsorbing compounds. For example, acetone wipes are used prior toapplication of sebashells to degrease the skin, especially to remove thesebum and follicular contents.

For certain subjects, delivery may be facilitated by reducing orclearing clogged follicles prior to application of the light absorbingmaterial. Such clearing can enhance the delivery of the nanoshells. Thefollicles, especially in acne prone patients, are clogged by shedkeratinocytes, sebum, and bacteria P. Acnes. The follicle can be emptiedby application of vacuum. Other methods are cyanoacrylate stripping,strips with components such as Polyquaternium 37 (e.g., Biore poreremoval strips). The polymers flow into the follicle and dry over time.When the dry polymer film is pulled out, the follicular contents arepulled out, emptying the follicle.

Optionally, the skin may be heated prior to application of the lightabsorbing compounds. Heating reduces the viscosity of the sebum and mayliquefy components of the sebum. This can facilitate delivery of lightabsorbing compounds (e.g., formulated as nanoshells) to the follicle.

Topical Delivery of Light Absorbing Compounds

Light absorbing compounds, such as non-toxic dyes (e.g., indocyaninegreen or methyelene blue) are topically applied to the skin followingany desired preparation. The topically applied formulations containingthe light absorbing materials may comprise ethanol, propylene glycol,surfactants, and acetone. Such additional components facilitate deliveryinto the follicle.

Delivery of light absorbing compounds is facilitated by application ofmechanical agitation, such as massage, acoustic vibration in the rangeof 10 Hz-20 kHz, ultrasound, alternating suction and pressure, and jets.In one embodiment, light absorbing compounds are delivered asnanoparticles, such as nanoshells or nanorods that absorb light in thevisible and the near-IR region of the electromagnetic spectrum. Inanother embodiment, light absorbing compounds are quantum dots.Preferably, the light absorbing compounds are formulated for topicaldelivery in a form that facilitates follicular delivery. In oneembodiment, such formulations comprise water, ethanol, isopropylalcohol, propylene glycol, surfactants, and isopropyl adipate andrelated compounds.

Ultrasound-Facilitated Delivery

Ultrasound has been used to achieve transdermal delivery of compoundsinto the body. Ultrasound appears to generate shock-waves and micro-jetsresulting from bubble cavitation that causes the formation of channelsin the skin, which provide for the transport of molecules of interest.Previous efforts have been directed toward the delivery of the compoundsthrough the stratum corneum. Small molecules, for example, with sizesless than 5 nm, can be delivered through the stratum corneum. Thedelivery rate through the stratum corneum goes down significantly asparticle size increases. For example, for particles with size of 50 nmand higher, the delivery rate through the stratum corneum is very low.However, this size is still much smaller than the pore opening and theinfundibulum of a follicle. For example, 150 nm size silica-core andgold shell structures are being used that are much smaller than theinfundibular diameter while showing low deposition in skin through thestratum corneum.

These findings provide the basis of acne treatment in which theinfundibulo-sebaceous unit is selectively targeted for first delivery oflight absorbing material of appropriate size and then selective thermaldamage to the unit with pulsed laser irradiation. Here, ultrasoundspecifically facilitates the delivery of a light absorbing compound intothe follicular structure. The shock waves, microjet formation, andstreaming deliver the light absorbing particles into the follicularinfundibulum and the associated sebaceous gland duct and the sebaceousgland.

Ultrasound is often be accompanied by heating of the target organ, skin.Some heating, for example, up to about 42° C. may help in folliculardelivery. However, excessive heating is undesirable, causing pain,tissue damage, and burns. In one embodiment, excessive heating can beavoided by cooling the skin, for example. In another embodiment, thetopically applied formulation or a coupling gel can be pre- orparallel-cooled. A low duty cycle with repeated ultrasound pulse burstscan also be used to avoid excessive heating, where during the off-time,the body cools the skin that is being subjected to ultrasound energy.

Acoustic cavitation is often an effect observed with ultrasound inliquids. In acoustic cavitation, a sound wave imposes a sinusoidallyvarying pressure upon existing cavities in solution. During the negativepressure cycle, the liquid is pulled apart at ‘weak spots’. Such weakspots can be either pre-existing bubbles or solid nucleation sites. Inone embodiment, a bubble is formed which grows until it reaches acritical size known as its resonance size (Leong et al., AcousticsAustralia, 2011—acoustics.asn.au, THE FUNDAMENTALS OF POWER ULTRASOUND—AREVIEW, p 54-63). According to Mitragotri (Biophys J. 2003; 85(6):3502-3512), the spherical collapse of bubbles yields high pressure coresthat emit shock waves with amplitudes exceeding 10 kbar (Pecha andGompf, Phys. Rev. Lett. 2000; 84:1328-1330). Also, an asphericalcollapse of bubbles near boundaries, such as skin yields microjets withvelocities on the order of 100 m/s (Popinet and Zaleski, 2002; J. Fluid.Mech. 464:137-163). Such bubble-collapse phenomena can assist indelivery of materials into skin appendages, such as hair and sebaceousfollicles. Thus, the invention provides methods for optimizing bubblesize before collapse to promote efficient delivery of light absorbingcompounds into the intended target (e.g., sebaceous glands, hairfollicles).

The resonance size of the bubble depends on the frequency used togenerate the bubble. A simple, approximate relation between resonanceand bubble diameter is given by F (in Hz)×D (in m)=6 m.Hz, where F isthe frequency in Hz and D is the bubble diameter (size) in m. Inpractice, the diameter is usually smaller than the diameter predicted bythis equation due to the nonlinear nature of the bubble pulsation.

Table 1 below gives the size of the resonance size of the bubble as afunction of frequency, calculated from the above relationship.

F, kHz 10 20 30 40 50 100 200 300 400 500 1,000 D_microns 600 300 200150 120 60 30 20 15 12 6Computer simulations of bubble oscillations give more accurate estimatesof the bubble size. For example, in work by Yasui (J. Acoust. Soc. Am.2002; 112: 1405-1413), three frequencies were investigated in depth. Thesizes for single bubble sonoluminescing (SBSL) stable bubbles are lowerand ranges are given in the following Table (estimated from FIGS. 1,2,and 3 of Yasui, 2002):

F, kHz 20 140 1,000 D_microns 0.2-200 0.6-25 0.2-6

For efficient delivery into the follicles with cavitation bubbles, thereis an optimal cavitation bubble size range. Strong cavitational shockwaves are needed, which are generated with relatively large bubbles.However, if the bubble size is too large, it produces strong shockwaves, which may compress the skin, reducing the pore size, and reducingefficient delivery to a target (e.g., sebaceous gland, follicle). Forexample, if the bubble size is much larger than the follicle opening,the resulting shock waves compress not only the pore opening, but alsothe skin surrounding the pore opening. This inhibits efficient deliveryinto the follicle opening. Desirably, bubble sizes should be about thesame size as the target pore. Typical pore sizes of follicles on humanskin are estimated to be in the range of 12-300 microns. Thus, thepreferred ultrasound frequency range is 20 kHz to 500 kHz. The desiredpower density is estimated to be in the range of 0.5-10 W/cm̂2. This issufficient to generate cavitation bubbles in the desired size range.

Energy (Light) Activation

After the topical application and facilitated delivery (e.g., bymechanical agitation, ultrasound), the top of the skin is wiped off toremove the residual light absorbing material. This is followed by energy(light) irradiation. The light is absorbed by the material inside thefollicle or sebaceous gland leading to localized heating. The lightsource depends on the absorber used. For example, for nanoshells thathave broad absorption spectrum tuned to 800 nm resonance wavelength,sources of light such as 800-nm, 755-nm, 1,064-nm or intense pulsedlight (IPL) with proper filtering can be used. Such pulsed laserirradiation leads to thermal damage to the tissue surrounding thematerial. Damage to infundibular follicular stem cells and/or sebaceousglands leads to improvement in the follicular conditions, such as acne.Such methods can be used not only for particulates in suspensions butfor small dissolved molecules in solution as well. These can includepharmaceutical drugs, photodynamic therapy (PDT) pro-drugs, or PDTdrugs.

Suitable energy sources include light-emitting diodes, incandescentlamps, xenon arc lamps, lasers or sunlight. Suitable examples ofcontinuous wave apparatus include, for example, diodes. Suitable flashlamps include, for example pulse dye lasers and Alexandrite lasers.Representative lasers having wavelengths strongly absorbed bychromophores, e.g., laser sensitive dyes, within the epidermis andinfundibulum but not sebaceous gland, include the short-pulsed red dyelaser (504 and 510 nm), the copper vapor laser (511 nm) and theQ-switched neodymium (Nd):YAG laser having a wavelength of 1064 nm thatcan also be frequency doubled using a potassium diphosphate crystal toproduce visible green light having a wavelength of 532 nm. In thepresent process, selective photoactivation is employed whereby an energy(light) source, e.g., a laser, is matched with a wave-length to theabsorption spectrum of the selected energy activatable material,preferably a chromophoric agent.

It is easier to achieve a high concentration of the light absorbingmaterial in the infundibulum than the sebaceous duct and the gland,which provide a higher resistance to material transport. The follicleincluding the sebaceous gland can be irreversibly damaged just relyingon light absorption principally but the material in the infundibulum.This is mediated through damage to the keratinocytes in the follicularepithelium. Also, with higher energy pulses can be used to extend thethermal damage to include the stern cells in the outer root sheath, thebulge, as well as the outside periphery of the sebaceous glands.However, such high energy should not lead to undesired side effects.Such side effects can be mitigated by use of cooling of the epidermisand also use of longer pulse durations, on the order of severalmilliseconds, extending up to 1,000 ms.

Thermal alteration of the infundibulum itself with only limitedinvolvement of sebaceous glands may improve acne. Appearance of enlargedpores on the face is a common issue for many. This is typically due toenlarged sebaceous glands, enlarged infundibulum, as well as enlargedpore opening. Heating of tissue, especially collagen, shrinks thetissue. The delivery of nanoshells and thermal targeting of the same inthe infundibulo-sebaceous unit that includes the upper, lowerinfundibulum, as well as the sebaceous gland, will improve theappearance of enlarged pores.

Energy Absorbing Compound Formulations

The invention provides compositions comprising light/energy absorbingcompounds for topical delivery. In one embodiment, a compound of theinvention comprises a silica core and a gold shell (150 nm). In anotherembodiment, nanoshells used are composed of a 120 nm diameter silicacore with a 15 micron thick gold shell, giving a total diameter of 150nm. The nanoshell is covered by a 5,000 MW PEG layer. The PEG layerprevents and/or reduces nanoshell aggregation, thereby increasing thenanoshell suspensions stability and shelf-life.

Nanoparticles of the invention exhibit Surface Plasmon Resonance, suchthat Incident light induces optical resonance of surface plasmons(oscillating electrons) in the metal. The Wavelength of peak absorptioncan be “tuned” to the near-infrared (IR) portion of the electromagneticspectrum. The submicron size of these nanoparticles allows their entryinto the infundibulum, sebaceous duct and sebaceous gland of theepidermis, and minimizes their penetration of the stratum corneum. Inparticular embodiment, selective transfollicular penetration ofnanoparticles ˜150-350 nm in diameter is achieved.

If desired, light/energy absorbing compounds are provided in vehiclesformulated for topical delivery. In one embodiment, a compound of theinvention is formulated with agents that enhance follicular delivery,including but not limited to, one or more of ethanol, isopropyl alcohol,propylene glycols, surfactants such as polysorbate 80, Phospholipon 90,polyethylene glycol 400, and isopropyl adipate. In other embodiments, acompound of the invention is formulated with one or more thickeningagents, including but not limited to, hydroxypropylcellulose (HPC) andcarboxymethyl cellulose (CMC), to enhance handling of the formulations.

Wetting agents, emulsifiers and lubricants, such as sodium laurylsulfate and magnesium stearate, as well as coloring agents, releaseagents, coating agents, sweetening and perfuming agents, preservativesand antioxidants can also be present in the compositions.

Liquid dosage forms for topical administration of the compounds of theinvention include pharmaceutically acceptable emulsions, microemulsions,solutions, creams, lotions, ointments, suspensions and syrups. Inaddition to the active ingredient, the liquid dosage forms may containinert diluents commonly used in the art, such as, for example, water orother solvents, solubilizing agents and emulsifiers, such as ethylalcohol, isopropyl alcohol, ethyl carbonate, ethyl acetate, benzylalcohol, benzyl benzoate, propylene glycol, 1,3-butylene glycol, oils(in particular, cottonseed, groundnut, corn, germ, olive, castor, peach,almond and sesame oils), glycerol, tetrahydrofuryl alcohol, polyethyleneglycols and fatty acid esters of sorbitan, and mixtures thereof.

Suspensions, in addition to the active compounds, may contain suspendingagents as, for example, ethoxylated isostearyl alcohols, polyoxyethylenesorbitol and sorbitan esters, microcrystalline cellulose, aluminummetahydroxide, bentonite, agar-agar and tragacanth, and mixturesthereof.

The ointments, pastes, creams and gels may contain, in addition to anactive compound of this invention, excipients, such as animal andvegetable fats, oils, waxes, paraffins, starch, tragacanth, cellulosederivatives, polyethylene glycols, silicones, bentonites, silicic acid,talc and zinc oxide, or mixtures thereof. The term “cream” is artrecognized and is intended to include semi-solid emulsion systems whichcontain both an oil and water. Oil in water creams are water miscibleand are well absorbed into the skin, Aqueous Cream BP. Water in oil(oily) creams are immiscible with water and, therefore, more difficultto remove from the skin. These creams are emollients, lubricate andmoisturize, e.g., Oily Cream BP. Both systems require the addition ofeither a a natural or a synthetic surfactant or emulsifier.

The term “ointment” is art recognized and is intended to include thosesystems which have oil or grease as their continuous phase. Ointmentsare semi-solid anhydrous substances and are occlusive, emollient andprotective. Ointments restrict transepidermal water loss and aretherefore hydrating and moisturizing. Ointments can be divided into twomain groups—fatty, e.g., White soft paraffin (petrolatum, Vaseline), andwater soluble, e.g., Macrogol (polyethylene glycol) Ointment BP. Theterm “lotion” is art recognized and is intended to include thosesolutions typically used in dermatological applications. The term “gel”is art recognized and is intended to include semi-solid permutationsgelled with high molecular weight polymers, e.g., carboxypolymethylene(Carbomer BP) or methylcellulose, and can be regarded as semi-plasticaqueous lotions. They are typically non-greasy, water miscible, easy toapply and wash off, and are especially suitable for treating hairy partsof the body.

Subject Monitoring

The disease state or treatment of a subject having a skin disease ordisorder can be monitored during treatment with a composition or methodof the invention. Such monitoring may be useful, for example, inassessing the efficacy of a particular agent or treatment regimen in apatient. Therapeutics that promote skin health or that enhance theappearance of skin are taken as particularly useful in the invention.

Kits

The invention provides kits for the treatment or prevention of a skindisease or disorder, or symptoms thereof. In one embodiment, the kitincludes a pharmaceutical pack comprising an effective amount of alight/energy absorbing compound (e.g., a nanoshell having a silica coreand a gold shell (150 nm)). Preferably, the compositions are present inunit dosage form. In some embodiments, the kit comprises a sterilecontainer which contains a therapeutic or prophylactic composition; suchcontainers can be boxes, ampules, bottles, vials, tubes, bags, pouches,blister-packs, or other suitable container forms known in the art. Suchcontainers can be made of plastic, glass, laminated paper, metal foil,or other materials suitable for holding medicaments.

If desired compositions of the invention or combinations thereof areprovided together with instructions for administering them to a subjecthaving or at risk of developing a skin disease or disorder. Theinstructions will generally include information about the use of thecompounds for the treatment or prevention of a skin disease or disorder.In other embodiments, the instructions include at least one of thefollowing: description of the compound or combination of compounds;dosage schedule and administration for treatment of a skin conditionassociated with acne, dermatitis, psoriasis, or any other skin conditioncharacterized by inflammation or a bacterial infection, or symptomsthereof; precautions; warnings; indications; counter-indications;overdosage information; adverse reactions; animal pharmacology; clinicalstudies; and/or references. The instructions may be printed directly onthe container (when present), or as a label applied to the container, oras a separate sheet, pamphlet, card, or folder supplied in or with thecontainer.

The recitation of a listing of chemical groups in any definition of avariable herein includes definitions of that variable as any singlegroup or combination of listed groups. The recitation of an embodimentfor a variable or aspect herein includes that embodiment as any singleembodiment or in combination with any other embodiments or portionsthereof.

The following examples are provided to illustrate the invention, not tolimit it. those skilled in the art will understand that the specificconstructions provided below may be changed in numerous ways, consistentwith the above described invention while retaining the criticalproperties of the compounds or combinations thereof,

Laser Hair Removal

The invention features compositions and methods that are useful forlaser hair removal, particularly in light colored hair. In laser hairremoval, a specific wavelength of light and pulse duration is used toobtain optimal effect on a targeted tissue with minimal effect onsurrounding tissue. Lasers can cause localized damage to a hair follicleby selectively heating melanin, which is a dark target material, whilenot heating the rest of the skin. Because the laser targets melanin,light colored hair, gray hair, and fine or thin hair, which has reducedlevels of melanin, is not effectively targeted by existing laser hairremoval methods. Efforts have been made to deliver various lightabsorbing compounds, such as carbon particles, extracts from squid ink,known commercially as meladine, or dyes into the follicle. These methodshave been largely ineffective.

The present invention provides microparticles in a suspension form thatis topically applied after skin preparation as delineated herein above.In particular, the skin is prepared by epilation of the hair shaft andlight absorbing compounds are delivered to the hair follicle.Preferably, the formulation is optimized for follicular delivery withmechanical agitation for a certain period of time. After wiping off theformulation from the top of the skin, laser irradiation is performed,preferably with surface cooling. The laser is pulsed, with pulseduration approximately 0.5 ms-400 ms using a wavelength that is absorbedby the nanoshells. This method will permanently remove unpigmented orlightly pigmented hair by destroying the stem cells and other apparatusof hair growth which reside in the bulge and the bulb area of thefollicle.

The practice of the present invention employs, unless otherwiseindicated, conventional techniques of molecular biology (includingrecombinant techniques), microbiology, cell biology, biochemistry andimmunology, which are well within the purview of the skilled artisan.Such techniques are explained fully in the literature, such as,“Molecular Cloning: A Laboratory Manual”, second edition (Sambrook,1989); “Oligonucleotide Synthesis” (Gait, 1984); “Animal Cell Culture”(Freshney, 1987); “Methods in Enzymology” “Handbook of ExperimentalImmunology” (Weir, 1996); “Gene Transfer Vectors for Mammalian Cells”(Miller and Calos, 1987); “Current Protocols in Molecular Biology”(Ausubel, 1987); “PCR: The Polymerase Chain Reaction”, (Mullis, 1994);“Current Protocols in Immunology” (Coligan, 1991). These techniques areapplicable to the production of the polynucleotides and polypeptides ofthe invention, and, as such, may be considered in making and practicingthe invention. Particularly useful techniques for particular embodimentswill be discussed in the sections that follow.

The following examples are put forth so as to provide those of ordinaryskill in the art with a complete disclosure and description of how tomake and use the assay, screening, and therapeutic methods of theinvention, and are not intended to limit the scope of what the inventorsregard as their invention.

EXAMPLES Example 1 Topical Delivery of Nanoshells to the FollicularEpithelium for the Treatment of Follicular Diseases

An example of massage as a mechanical means of follicular delivery isdescribed. Nanoshell suspension tuned to 800-nm was massaged in anepilated pig skin in an in vivo live pig. Laser energy with parallelcontact cooling was applied after wiping off the suspension on the topof the skin. A biopsy was taken, and routine histology was performed. Amicrograph of the histology is shown at FIG. 1. Thermal damage to thefollicular epithelium and part of the sebaceous gland is noted. Suchdamage is useful for the treatment of follicular diseases, such as acne,

Example 2 Topical Delivery of Nanoshells to the Follicular Epitheliumfor Laser Hair Removal

In preparation for laser hair removal, a pig flank was epilated bywaxing. Skin was subsequently heated, and a vacuum was applied to emptythe follicular contents of the skin. Silica core: gold shellmicroparticles, of approximate dimensions of 0.150 micrometers diametercoated with PEG were then delivered by massaging. Skin was wiped toremove the material from the top of the skin. This was followed bypulsed laser irradiation at 800 nm. Samples were excised, fixed informalin, and processed via routine histology (H&E staining). Thermalinjury to the follicular structure was noted via histology.

Example 3 Light-Pulse Induced Pressure Pulse Facilitated Delivery

A formulation containing a light-absorbing material is applied on top ofskin. This is moved into the infundibulum of the infundibulo-sebaceousunit by methods known in the art, including but not limited to, passivediffusion, heating, mechanical assistance such as pressure pulsing,vibration, acoustic coils, ultrasound, nozzles or a combination of theabove. Then, pulses of light are applied with a handpiece with anintegrated cooling plate that can be pressed on to the skin. The firstpulse(s) of light heat the material, resulting in expansion, with orwithout steam bubble formation. A pressure pulse is thereby created.Pressure is applied to the skin by the plate during the pressure pulse.Because the pressure cannot escape from the skin, the material flowsthrough low resistance channels within the skin, such as the sebaceousgland duct, to reach the sebaceous gland. This pulse typically has shortpulse duration, e.g., 1 ns-1 ms, preferably, 10 ns-100 microseconds, tomaximize the magnitude of the pressure pulse, for example, through steambubble formation. Once the material is within the target sebaceousgland, light is applied with a pulse duration and radiant exposureappropriate to the size of the sebaceous glands being targeted. Thelight absorbing material is heated, causing thermal damage to thesebaceous gland, thus inactivating it, and causing improvement in acnevulgaris and other follicular diseases and conditions associated withthe presence or activity of sebaceous glands.

In a related approach, a train of low-energy laser pulses, 1 microsecondor less in pulse duration, preferably in the acoustic range for pulserepetition rate, is used to activate the particles. This activationviolently ‘stirs’ the particles, some of which will be propelled fromthe infundibulum into the sebaceous glands.

Example 4 Use of Ultrasound to Deliver Light Absorbing Material to theFollicle and Sebaceous Glands

Pig ear skin was kept frozen. Before the experiment, it was thawed. Hairwas epilated with waxing and a piece of the pig ear with skin facing upwas placed at the bottom of a cup. It was filled with formulation of150-nm diameter silica-core/gold-shell nanoshells (Sebacia, Inc.,Duluth, Ga.) with an optical density of approximately 250. A Sonics, 20kHz device horn was immersed into the formulation so that the distancebetween the far surface of the horn at the top of the skin wasapproximately 5-mm. The horn diameter was 13 mm and the power output wasapproximately 6 W. Thus, the power density during the on-time was 4.5W/cm2. The device was turned on with 50% duty cycle, with the on-timeand off-time per cycle of 5 s and 5 s, respectively. Four cycles wereapplied. After wiping the skin to remove excess formulation, the skinwas irradiated with laser light at 800-m wavelength with a 9 mm×9 mmspot, approximately 50 J/cm2 total radiant exposure, and 30-ms pulseduration.

The skin was observed via a dissecting microscope and photographs weretaken (FIG. 2). Cuts perpendicular to the skin surface were made throughfollicle openings and the cut surface was observed through an opticalmicroscope (FIG. 3). Some samples were placed in 10% buffered formalinsolution and observed via routine histology (FIG. 4).

The skin was intact and unperturbed except punctuate dots were noted onthe follicle openings (FIG. 2). Upon cutting and observing through amicroscope, the presence of dark nanoshells was noted within thefollicle infundibulum, as well as in the sebaceous glands (FIG. 3). Nonanoshells were seen in the epidermis or the dermis surrounding thefollicles. Similarly, histology showed thermal damage to the follicularinfundibulum and the sebaceous glands (FIG. 4). There was no or minimaldamage to the epidermis and the dermis surrounding the follicles.

Example 5 Ultrasound Facilitated Delivery

A transducer from APC International of Mackeyville, Pa. was driven by asinusoidal wave of 300 Vp-p from a waveform generator and an amplifierwith 500 Ohm source impedance. A formulation of 250 OD (F78, Sebacia,Inc.) containing the 150 nm diameter silica core: gold shell was placedtopically on epilated pig ear skin. This was followed by wiping of thetop surface and laser irradiation with Lumenis Lightsheer at 800 nm. Theskin temperature was noted after the ultrasound application and did notexceed 41° C.

Significant accumulation of the nanoshells in the follicles was noted(FIG. 5). Vertical cuts were made through follicles and the cut surfaceswere observed under a microscope. An exemplary follicle is shown in FIG.6. A significant accumulation of nanoshells inside and outside theinfundibulum is noted.

Histological analysis of a sample is shown in FIG. 7. Localized thermaldamage to the follicle including thermal damage to the sebaceous glandsis observed (FIG. 7).

Example 6 Human Clinical Efficacy Demonstrated in Back Acne

The efficacy of nanoshell topical delivery followed by laser treatmentwas evaluated in a clinical study of back acne. Nanoshells weretopically applied to the back of each subject and laser treatment wasinitiated as described herein above. This treatment regimen wasadministered twice to each subject. Results were evaluated twelve weeksfollowing the second treatment. Efficacy was determined by weightedinflammatory lesion counts. Results are shown in FIG. 8. This study ofback acne study indicates that the treatment regimen was clinicallyeffective.

Example 7 Human Clinical Efficacy Demonstrated in Sebaceous Gland Damage

IRB approved human clinical studies have been carried out in seventeensubjects (6 males, 11 females) with acne. The subjects range in age from18-40 years (mean 24 years) phototype I-IV. Treatment was carried out ona 1 square inch area behind ear (sebaceous follicles). Nanoshells weredelivered followed by laser treatment, where the laser was tuned to thenanoshell's absorption peak (40-50 J/cm2, 30-ms, 9×9 mm, LightSheer (800nm)). Therapeutic efficacy was histologically evaluated in 31 biopsies,where 4-7 follicles were present in each biopsy. A 4 mm punch biopsy wastaken, serially sectioned, and damage to sebaceous follicle wasvisualized by H&E staining. Pain, erythema, edema minimal. Localizeddamage was observed in ˜60% of sebaceous follicles. In some specimens,destruction of the entire sebaceous gland was observed. The depth ofthermal damage in follicles was on average 0.47 mm (maximum 1.43 mm). Nocollateral damage to epidermis or dermis was observed. In-vivo histologystudy damage to infundibulum, bulge and sebaceous glands was observedafter treatment.

Example 8 Ultrasound Facilitated Delivery of Photodynamic Therapy (PDT)with Aminolevulinic Acid (ALA)

In experiments with ultrasound, the follicle provided easier access fordelivery of light absorbing compounds than the stratum corneum. This maybe due to a differential in the transport rates into the stratum corneumand the follicle. This difference can be exploited to facilitateselective delivery of smaller molecules. This approach can be used foreither chromophores in a photothermal treatment regimen or forphotodynamic therapy with compounds or prodrugs leading to photodynamiceffect. For example, convention acne therapies involving ALA-PDTtreatment require long incubation times (on the order of 3-4 hours) todeliver sufficient concentration of ALA to the sebaceous glands toachieve the desired clinical efficacy.

This treatment results in significant adverse side effects, includingepidermal crusting, pain, and long-lasting redness. This extendedincubation period results in the delivery of ALA to non-target areas ofthe epidermis and the dermis. Ultrasound-assisted delivery can beaccomplished without these long incubation periods, while stillachieving sufficient concentrations in the target infundibulo-sebaceousunit. Because the long incubation period is eliminated with ultrasounddelivery, little ALA is delivered to the non-target epidermis anddermis. After ultrasound delivery, the ALA formulation can be removedfrom the skin surface. The light irradiation is performed oncesufficient time has passed to ensure that concentrations of thephotoactive material have reached adequate levels in the target volume.In photothermal treatments, pulsed laser irradiation can be initiatedsoon after delivery.

In another embodiment, compounds of interest are attached tomicroparticles and delivered to the target volume. Light irradiation maybe used to disassociate the compound, leading to its diffusion andsubsequent action. Formation of cavitation bubbles is facilitated by thepresence of nanoparticles that “seed” bubble formation. Also, deliverycan be facilitated by the use of volatile components such as ethanol.

Example 9 Formulations

Various nanoshells formulation were tested in an ex vivo skin model. Thecomponents tested were designed to enhance delivery into follicles.Formulation constituents were ethanol, isopropyl alcohol, propyleneglycols, surfactants such as polysorbate 80, Phospholipon 90,polyethylene glycol 400, isopropyl adipate. Compatibility of theseamongst each other was tested. Three classes were identified:hydrophilic, lipophilic, and liposomal. The absorption coefficient ofthe formulation is suggested to be in the range of 10 to 1,000 inversecm. Four example formulations were tested in an in vivo pig skin model;the compositions are as in Table 1 below.

TABLE 1 Table showing compositions of four of the formulations tested ina human back acne study. Components F74 F76 F78 F80 PEGylated nanoshellsuspension in  12%  25%  25%  65% water (Optical density ~1,100- 1,200)Ethyl Alcohol 190 proof  73%  55%  54%  20% Propylene Glycol  5%  10% 5% Polysorbate 80  1%  9%  1%  9% Benzyl Alcohol  9%  1%  1%Diisopropyl Adipate  20% Total 100% 100% 1.00% 100%

Other Embodiments

From the foregoing description, it will be apparent that variations andmodifications may be made to the invention described herein to adopt itto various usages and conditions. Such embodiments are also within thescope of the following claims.

The recitation of a listing of elements in any definition of a variableherein includes definitions of that variable as any single element orcombination (or subcombination) of listed elements. The recitation of anembodiment herein includes that embodiment as any single embodiment orin combination with any other embodiments or portions thereof.

This application includes subject matter that may be related to subjectmatter described in U.S. Ser. No. 12/787,655, US Patent Publication No.2012/0059307, and U.S. Pat. No. 6,183,773, each of which is incorporatedherein in its entirety. All patents and publications mentioned in thisspecification are herein incorporated by reference to the same extent asif each independent patent and publication was specifically andindividually indicated to be incorporated by reference.

1. A method of localizing thermal damage to a pilosebaceous unit,comprising: topically applying a solution of unassembled plasmonicnanoparticles to a skin surface, wherein the plasmonic nanoparticlescomprise a conductive metal portion, wherein the conductive metalportion comprises at least one of gold, silver, nickel, platinum, andtitanium, wherein the plasmonic nanoparticles comprise a coating thatcoats the conductive metal portion, wherein said coating is hydrophilic;wherein the solution of unassembled plasmonic nanoparticles has anoptical density of at least about 1 O.D. at one or more peak resonancewavelengths; distributing the solution from the skin surface to aportion of a pilosebaceous unit; removing the solution from the skinsurface while leaving the solution localized within the portion of thepilosebaceous unit; and irradiating the solution with an energywavelength in the near-infrared range thereby inducing a surface plasmonin said plasmonic nanoparticles, thereby localizing thermal damage tosaid portion of the pilosebaceous unit.
 2. The method of claim 1,further comprising: pre-treating the skin surface, prior to irradiating,to increase distribution from the skin surface to the pilosebaceousunit, wherein pre-treating the skin surface comprises at least one ofthe group consisting of: hair removal and fractionated photothermolysislaser treatment.
 3. The method of claim 1, wherein distributing thesolution of plasmonic nanoparticles comprises distribution with amechanical vibration device, wherein the mechanical vibration devicecomprises an ultrasound device.
 4. (canceled)
 5. The method of claim 1,wherein the portion of the pilosebaceous unit comprises one or morestructures consisting of: a hair follicle, a sebaceous gland, and a hairfollicle infundibulum.
 6. The method of claim 1, wherein the solution ofunassembled plasmonic nanoparticles has an optical density of at leastabout 1 O.D. at a resonance wavelength of about 810 nanometers. 7.(canceled)
 8. The method of claim 1, wherein the solution of unassembledplasmonic nanoparticles has an optical density of about 250 O.D.
 9. Themethod of claim 1, wherein the conductive metal portion comprises gold.10. The method of claim 1, wherein the conductive metal portioncomprises silver. 11.-13. (canceled)
 14. The method of claim 1, whereinthe plasmonic nanoparticles are nanoshells.
 15. The method of claim 1,wherein the nanoshells have a diameter of about 150 nm.
 16. The methodof claim 15, wherein the nanoshells comprise a silica core and a goldshell.
 17. The method of claim 16, wherein the silica core has adiameter of 120 nm.
 18. The method of claim 16, wherein the gold shellhas a thickness of 15 nm.
 19. The method of claim 1, wherein the coatingcomprises polyethylene glycol (PEG).
 20. A method of localizing thermaldamage to a pilosebaceous unit, comprising: topically applying asolution of unassembled plasmonic nanoparticles to a skin surface;wherein the solution of plasmonic nanoparticles has at least one peakabsorption wavelength in the near-infrared range, wherein the thesolution of unassembled plasmonic nanoparticles has an optical densityof at least about 1 O.D. at one or more peak resonance wavelengths,wherein the plasmonic nanoparticles comprise a conductive metal portion,wherein the conductive metal portion comprises at least one of gold,silver, nickel, platinum, and titanium, wherein the plasmonicnanoparticles comprise a coating that coats the conductive metalportion, wherein said coating is hydrophilic; targeting a pilosebaceousunit by redistributing the solution of plasmonic nanoparticles from theskin surface to the pilosebaceous unit, wherein redistributing solutionof plasmonic nanoparticles comprises distribution with a mechanicalvibration device; removing the solution from the skin surface whileleaving the solution localized within the pilosebaceous unit; andexposing the solution of plasmonic nanoparticles to an energy source toinduce a surface plasmon in said plasmonic nanoparticles, therebylocalizing thermal damage to said pilosebaceous unit. 21.-34. (canceled)35. A method of treating a pilosebaceous unit, comprising: pre-treatinga skin surface to increase delivery of a solution of unassembledplasmonic nanoparticles to a portion of a pilosebaceous unit, applyingthe solution of unassembled plasmonic nanoparticles to the skin surface,wherein the plasmonic nanoparticles comprise at least one of gold,silver, nickel, platinum, and titanium, distributing the solution ofunassembled plasmonic nanoparticles from the skin surface to the portionof the pilosebaceous unit; wherein the solution of unassembled plasmonicnanoparticles has an optical density of at least about 1 O.D. at one ormore peak resonance wavelengths, wherein the plasmonic nanoparticlescomprise a coating, wherein said coating is hydrophilic, removing thesolution from the skin surface while leaving the solution localizedwithin the portion of the pilosebaceous unit, and exposing the solutionof plasmonic nanoparticles to an energy wavelength in the near-infraredrange to induce a surface plasmon in said plasmonic nanoparticles,thereby localizing thermal damage to said portion of the pilosebaceousunit. 36.-50. (canceled)
 51. A method of treating a pilosebaceous unit,comprising: pre-treating a skin surface to increase delivery ofunassembled plasmonic nanoparticles to a portion of a pilosebaceous unitapplying a solution of unassembled plasmonic nanoparticles to the skinsurface, distributing the solution from the skin surface to the portionof the pilosebaceous unit; wherein the solution of unassembled plasmonicnanoparticles has an optical density of at least about 1 O.D. at one ormore peak resonance wavelengths; wherein the plasmonic nanoparticlescomprise at least one of gold, silver, nickel, platinum, and titanium,wherein the plasmonic nanoparticles comprise a coating, selectivelyremoving the solution from the skin surface while leaving the solutionlocalized within the portion of the pilosebaceous unit, and exposing thesolution of plasmonic nanoparticles to an energy wavelength in thenear-infrared range to induce a surface plasmon in said plasmonicnanoparticles, thereby localizing thermal damage to said portion of thepilosebaceous unit. 52.-55. (canceled)
 56. A method of localizingthermal damage to a pilosebaceous unit, comprising: topically applying asolution of unassembled plasmonic nanoparticles to a skin surface,wherein the plasmonic nanoparticles comprise a conductive metal portion,wherein the conductive metal portion comprises at least one of gold,silver, nickel, platinum, and titanium, wherein the plasmonicnanoparticles comprise a coating that coats the conductive metalportion, wherein the solution of unassembled plasmonic nanoparticles hasan optical density of at least about 1 O.D. at one or more peakresonance wavelengths; wherein said concentration is sufficient to,after exposure an energy wavelength, induce thermal damage in a portionof a pilosebaceous unit; distributing the solution from the skin surfaceto the portion of the pilosebaceous unit; selectively removing thesolution from the skin surface, while leaving the solution localizedwithin the portion of the pilosebaceous unit; and exposing the solutionwith an energy wavelength in the near-infrared range thereby inducing asurface plasmon in said plasmonic nanoparticles, thereby localizingthermal damage to said portion of the pilosebaceous unit. 57.-63.(canceled)
 64. A method of localizing thermal damage to a pilosebaceousunit, comprising: providing a solution of unassembled plasmonicnanoparticles configured for topical application to a skin surface;wherein the solution of plasmonic nanoparticles has at least one peakabsorption wavelength in the near-infrared range, wherein the solutionof unassembled plasmonic nanoparticles has an optical density of atleast about 1 O.D. at one or more peak resonance wavelengths; whereinthe plasmonic nanoparticles comprise a conductive metal portion, whereinthe conductive metal portion comprises at least one of gold, silver,nickel, platinum, and titanium, wherein the plasmonic nanoparticlescomprise a coating that coats the conductive metal portion; targeting apilosebaceous unit by redistributing the solution of plasmonicnanoparticles from the skin surface to the pilosebaceous unit;selectively removing the solution from the skin surface, while leavingthe solution localized within the pilosebaceous unit; and exposing thesolution of plasmonic nanoparticles to an energy source to induce asurface plasmon in said plasmonic nanoparticles, thereby localizingthermal damage to said pilosebaceous unit.
 65. A method for performingthermoablation, comprising the steps of contacting a target tissueregion of a mammalian subject with a composition comprising a pluralityof plasmonic nanoparticles under conditions such that an effectiveamount of the plasmonic nanoparticles localize to a domain of the targettissue region; and exposing the target tissue region to energy deliveredfrom a nonlinear excitation surface plasmon resonance source in anamount effective to induce thermoablation of the domain of the targettissue region, wherein: the composition is formulated for topicaladministration; the nanoparticle comprises a nanoshell, a nanorod, or ananowire; the size of the nanoparticle is about 150 to about 350 nm; thenanoparticle comprises a coating on a surface of the nanoparticle; thenanoparticle comprises a coating on a surface of the nanoparticle,wherein the coating comprises a protein or a peptide; the nanoparticlecomprises a coat on a surface of the nanoparticle, wherein the coatingis hydrophilic; the composition is topically administered, wherein thetopical administration comprises the use of mechanical agitation,acoustic vibration, ultrasound, alternating suction and pressure, ormicrojets; the nanoparticle has an optical absorption of about 800 nm;or the plasmonic nanoparticle comprises a composite comprising a metaland a dielectric or a metal and a semiconductor. 66.-73. (canceled)